Researchers develop durable plastic that may replace metals

As landfills overflow with discarded plastics, scientists
have been working to produce a biodegradable alternative that will reduce
pollution. Now a Tel Aviv University (TAU) researcher is giving the quest for
environmentally friendly plastics an entirely new dimension—by making them
tougher than ever before.

Professor Moshe Kol of TAU's School of Chemistry
is developing a super-strength polypropylene—one of the world's most commonly
used plastics—that has the potential to replace steel and other materials used
in everyday products. This could have a long-term impact on many industries,
including car manufacturing, in which plastic parts could replace metallic car
parts.

Durable plastics consume less energy during the production
process, explains Kol. And there are additional benefits as well. If
polypropylene car parts replaced traditional steel, cars would be lighter
overall and consume less fuel, for example. And because the material is cheap,
plastic could provide a much more affordable manufacturing alternative.

His research has been published in Angewandte Chemie.

Better
building blocks

Although a promising field of research, biodegradable plastics
have not yet been able to mimic the durability and resilience of common, non-biodegradable
plastics like polypropylene. Kol believes that the answer could lie in the
catalysts, the chemicals that enable their production.

Plastics consist of very long chains called polymers, made of
simple building blocks assembled in a repeating pattern. Polymerization
catalysts are responsible for connecting these building blocks and create a
polymer chain. The better the catalyst, the more orderly and well-defined the
chain—leading to a plastic with a higher melting point and greater strength and
durability. This is why the catalyst is a crucial part of the plastic
production process.

Kol and his team of researchers have succeeded in developing
a new catalyst for the polypropylene production process, ultimately producing
the strongest version of the plastic that has been created to date.
"Everyone is using the same building blocks, so the key is to use
different machinery," he explains. With their catalyst, the researchers
have produced the most accurate or "regular" polypropylene ever made,
reaching the highest melting point to date.

Using
resources more efficiently

By 2020, the consumption of plastics is estimated to reach 200
million tons a year. Kol says that because traditional plastics aren't
considered green, it's important to think creatively to develop this material,
which has become a staple of daily life, with the least amount of harm to the
environment. Cheaper and more efficient to produce in terms of energy
consumption, as well as non-toxic, Kol's polypropylene is good news for green
manufacturing and could revolutionize the industry. The durability of the
plastic results in products that require less maintenance—and a much longer
life for parts made from the plastic.

Beyond car parts, Kol envisions a number of uses for this
and related plastics, including water pipes, which he says could ultimately
conserve water use. Drinking water for the home has been traditionally carried
by steel and cement pipes. These pipes are susceptible to leakage, leading to
waste and therefore higher water bills. But they are also very heavy, so
replacing them can be a major, expensive operation.

"Plastic pipes require far fewer raw materials,
weighing ten times less than steel and a hundred times less than cement.
Reduced leaking means more efficient water use and better water quality," Kol
explains. The replacement of steel water pipes by those made of plastic is
becoming more common, and the production of plastics with even greater strength
and durability will make this transition even more environmentally friendly.